In the days after the inauguration that marked the total takeover of the federal government by the other side, they rose up across the nation, overtaking streets and parks and town halls held by their representatives. Then they dug in deeper, channeling their rage into action and organizing a grassroots movement that produced candidates—new faces, with new messages—who began to seize control of elected offices. A trickle became a flood that reshaped American politics.

This description applies to the Resistance—which in last week's elections proved that pussy hats deliver—but also to the Tea Party, which coalesced in the first year of the Obama administration and then seized control of the House, and the Republican Party, come midterms. According to Harvard political scientist Theda Skocpol, the Resistance is now as strong as the Tea Party at its peak, with 250,000 to 300,000 active members—which, to many, makes the Democrats’ 2018 prospects seem rosy, and a wave election seem a very likely outcome.

“Groups in [red states] are organizing rallies, and showing up for neighbors and progressive causes. And they are energized. They are ready. And I think it’s absolutely possible to take control of the House in 2018,” Maria Urbina, political director at Indivisible—perhaps the most famous Resistance group—told me.

But the Resistance has to contend with something the Tea Party doesn’t: the map. In a system weighted, by Constitutional design, to give rural areas disproportionate influence, Democrats’ hopes in 2018 remain hazy. Nearly all of Tuesday night’s wins were recorded in urban areas, the suburbs just outside them, or densely populated blue or blueish purple states. Meanwhile, in many rural areas, in states both red and blue, “if you talk about being a Democrat, you might get your tires shot out,” newly minted Alabama Resistance member Joan Williams told me.

Like continental drift, the rural-urban political and cultural divide has been slowing growing wider, and more sclerotic, for decades. But the fissures in the country’s landscape became more obvious than ever in 2016, when Hillary Clinton took just 487 counties to Donald Trump’s 2,626. And because Clinton’s support clustered in wealthier, more educated, and more urban areas, Clinton won the popular vote but lost the electoral college, which amplifies the vote in sparsely populated states. (For example, a presidential vote in Wyoming counts more than three times as much as one in California.) Republicans also maintained control of the Senate even though they got fewer votes than Democrats because less populated states get just as many Senate seats as high-population deep-blue states (a Wyoming Senate vote counts roughly 67 times as much as one in California).

The House, where seats are divided up between states based on population, should be more small-d democratic. But thanks to gerrymandering, many states’ congressional maps now resemble a Jackson Pollack painting, with district lines stretched and zig-zagged to privilege Republicans over Democrats. (This is a result of the GOP controlling so many statehouses and thus the redistricting process.) That’s on top of the handicap Democrats face because they are concentrated in cities instead of spread out like rural Republican voters. As a result, in 2016 the Republicans won the House popular vote by just 1 percent yet hold a whopping 47-seat majority. That means Democrats will have to really whip Republicans to take the House back in 2018—according to an estimate from FiveThirtyEight, they could win the popular vote by as much as 7 percent and still not gain control.

In short, rural voters have a big advantage over urban ones. That means if the red-blue divide remains a starkly rural-urban one, American progressives, like women worldwide, are going to have to work twice as hard and be twice as smart to reap the same midterm results as the right did in 2010.

That’s not to say that there’s no chance. Resistance groups are popping up all over the country, and they aren’t confined to deep-blue Clinton strongholds. Indivisible now has nearly 6,000 branches, including at least two in every Congressional district.

That’s a corrective to a decade-long trend where Democrats conceded large swathes of the country to Republicans. Barack Obama has come under fire for letting the party give up on the “50-state strategy” and allowing the Democratic National Committee to atrophy, which likely helped Republicans seize so many state offices that they have complete power in 26 states.

“In some places, they haven’t heard from [Democratic] operatives or officials or candidates in a long time. Or just haven’t had Democrats competing,” said Indivisible’s Urbina. “Our electoral strategy is to support our groups in what they view as most important in their local community—give them tools and guidance. And our members are not only rebuilding infrastructure, they are also running for office.”

Last week shows that they can score real victories.

Wilmont Collins, a black Liberian refugee, ran for mayor in Helena, Montana, a 95 percent white city in a county that voted for Trump by a seven-point margin—and he managed to unseat the four-term incumbent. While Helena is, as the state capital, inherently somewhat urban, with a population of 31,000 it is far from Clinton country. So what does Collins think progressives might learn from his success?

“One thing I will say to anyone running for office is spend less time on Facebook and Twitter, and more time talking with a diverse group of voters,” he told me. “I ran on a progressive platform and ideas that I believe can make Helena a more enjoyable place for a wider array of citizens.”

Joan Williams, 59, had never been an activist before 2017. And until recently, she was a registered Republican. But as of this week, she will be working full-time to get Jones across the finish line. “My husband and I hadn’t even voted in a primary until this year,” she told me. Why the change? “In a word, Trump.”

She says her Indivisible group in rural Limestone County, where Trump won by a 50-point margin, is not yet focused on changing hearts in minds—but she believes their grassroots get-out-the vote efforts could help push Jones over the top statewide. “There are a lot of Democrats around here, but are so beat down and think they don’t have a chance, so they don’t vote,” she said.

In other words, that rural-urban divide is likely going to persist—at least in the short term. But for Democrats to win in 2018, they’re going to need to ignore that division and fight everywhere.